In situ chemical oxidation of contaminated groundwater by persulfate: decomposition by Fe(III)- and Mn(IV)-containing oxides and aquifer materials.
In situ chemical oxidation of contaminated groundwater by persulfate: decomposition by Fe(III)- and Mn(IV)-containing oxides and aquifer materials.
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DOI：
10.1021/es502056d
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发表时间：
2014-09-02
影响因子：
11.4
通讯作者：
Sedlak, David L.
中科院分区：
文献类型：
--
作者：
Liu, Haizhou;Bruton, Thomas A.;Doyle, Fiona M.;Sedlak, David L.
过硫酸盐(S2O82-)被越来越多地用于地下水中有机污染物的原位化学氧化(ISCO)，尽管对其转化为活性物种的机理尚不完全了解。特别是，天然矿物表面对过硫酸盐的分解还没有详细的研究。为了深入了解地下过硫酸盐分解的反应速率和机理，并确定提高其效率的可能方法，在有无苯的情况下，研究了在有无苯的情况下，在纯金属氧化物、粘土和野外现场收集的代表性含水层固体存在下过硫酸盐的分解。在典型的地下水条件下，Fe(III)-和Mn(IV)-氧化物催化过硫酸盐转化为硫酸根(SO4·-)和羟基自由基(HO·)的时间尺度为数周，比在无金属体系中观察到的速度快2-20倍。无定形水合铁是过硫酸盐分解反应最活跃的铁矿物，其反应速度与固体质量和表面积成正比。当苯的浓度超过0.1 mM时，由于自由基链式反应，过硫酸盐的分解速度增加了100倍。由于过硫酸盐在地下的分解速度相对较慢，将过硫酸盐注入地下水可能是有利的，使其能够迁移到渗透系数低的区域，在那里粘土、金属氧化物和污染物将加速其转化为活性氧化剂。
Persulfate (S2O82–) is being used increasingly for in situ chemical oxidation (ISCO) of organic contaminants in groundwater, despite an incomplete understanding of the mechanism through which it is converted into reactive species. In particular, the decomposition of persulfate by naturally occurring mineral surfaces has not been studied in detail. To gain insight into the reaction rates and mechanism of persulfate decomposition in the subsurface, and to identify possible approaches for improving its efficacy, the decomposition of persulfate was investigated in the presence of pure metal oxides, clays, and representative aquifer solids collected from field sites in the presence and absence of benzene. Under conditions typical of groundwater, Fe(III)- and Mn(IV)-oxides catalytically converted persulfate into sulfate radical (SO4•–) and hydroxyl radical (HO•) over time scales of several weeks at rates that were 2–20 times faster than those observed in metal-free systems. Amorphous ferrihydrite was the most reactive iron mineral with respect to persulfate decomposition, with reaction rates proportional to solid mass and surface area. As a result of radical chain reactions, the rate of persulfate decomposition increased by as much as 100 times when benzene concentrations exceeded 0.1 mM. Due to its relatively slow rate of decomposition in the subsurface, it can be advantageous to inject persulfate into groundwater, allowing it to migrate to zones of low hydraulic conductivity where clays, metal oxides, and contaminants will accelerate its conversion into reactive oxidants.
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影响因子：
11.4
作者：
Lau, Tim K.;Chu, Wei;Graham, Nigel J. D.
通讯作者：
Graham, Nigel J. D.
DOI：
10.1039/ft9908602557
发表时间：
1990-07-21
期刊：
JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS
影响因子：
--
作者：
MCELROY, WJ;WAYGOOD, SJ
通讯作者：
WAYGOOD, SJ
影响因子：
12.8
作者：
Deng, Yang;Ezyske, Casey M.
通讯作者：
Ezyske, Casey M.
影响因子：
2
作者：
Liang, CJ;Bruell, CJ;Sperry, KL
通讯作者：
Sperry, KL
影响因子：
8.8
作者：
Liang, Chenju;Huang, Chiu-Fen;Kurakalva, Rama Mohan
通讯作者：
Kurakalva, Rama Mohan